Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net (loss)/income	$ (25,880)	$ 4,152	$ 2,479	$ 8,824	$ (11,564)	$ 22,049	$ 16,724	$ 9,424	$ (10,425)		$ 36,633	$ 27,199
Less: Income distributed to participating securities									(2,163)		(1,595)	(696)
Less: Undistributed income allocable to participating securities											(1,409)
Net (loss)/income available to common stockholders – Basic EPS									$ (12,588)		$ 33,629	$ 26,503
Weighted average common shares (in thousands)									151,823		146,645	134,614
Basic (loss)/earnings per share	$ (0.17)	$ 0.02	$ 0.01	$ 0.05	$ (0.08)	$ 0.13	$ 0.10	$ 0.07	$ (0.08)		$ 0.23	$ 0.20
Net (loss)/income available to common stockholders									$ (12,588)		$ 33,629	$ 26,503
Add back: Undistributed income allocable to participating securities											1,409
Less: Reallocation of undistributed income allocable to participating securities considered potentially dilutive											(1,403)
Net (loss)/income available to common stockholders – Diluted EPS									$ (12,588)		$ 33,635	$ 26,503
Weighted average common shares									151,823		146,645	134,614
Dilutive effect of common stock equivalents, excluding participating securities											645	944
Weighted average diluted shares									151,823	[1]	147,290	135,558
Diluted earnings per share	$ (0.17)	$ 0.02	$ 0.01	$ 0.05	$ (0.08)	$ 0.13	$ 0.10	$ 0.07	$ (0.08)		$ 0.23	$ 0.20

[1] Excludes participating securities and potentially dilutive common stock equivalents as the Company reported a net loss for the period.